10 Articles Published

1. EVALUATION OF REAL-TIME POSTERIOR VISUAL FEEDBACK FOR POSTURAL CORRECTION DURING SMARTPHONE USE

Authors: IM JONG-HUN , YU JAE-HO

Abstract: As abnormal posture caused by prolonged smartphone use increases, its related disease also increases. It is time to prevent this problem. This study aim to figure out how much real-time visual feedback has an effect on postural correction. Healthy 34 participants were instructed to keep neutral posture and then use smartphone. Each participant was instructed to maintain a neutral posture with their elbows positioned in line with the trunk and flexed 90–120˚ and keep the trunk upright, chin tucked, scapula slightly protracted and depressed and sole of the foot on the floor 1) for 15 minutes in non feedback condition, after 3 minutes resting period, 2) for 15 minutes in visual feedback condition while maintaining their original posture. When participants consciously apply feedback for postural correction, participants can check the movement of scapula and forward head level as they apply posterior visual feedback. The result of this study had a significant difference in the meaning of

Keywords: Smartphone, Visual feedback, Forward head posture, Abnormal posture, Postural correction

Pages: 1 - 5 | DOI: 10.15224/978-1-63248-140-5-34

2. A STUDY ON A PALLARAX ERROR AND ITS DISPERSION ON THE TARGET

Authors: GUN IN KIM , HWAN IL KANG , HYUN SOO KIM

Abstract: There are many errors to affect the system hit probability. Fixed bias, variable bias and random error are main categories for many errors. In this paper, a parallax error is considered. The parallax error belongs to the fixed bias. The fixed bias cannot be controlled by the shooting control device. The parallax error depends on the distance between the positions of the EOTS (electronic optical tracking device) and the gun. We calculate the error effect at the target by using the mil unit. The definition of a mil is based on a unit circle with a radius of one and 6400 mils mean the circumference in one turn. This analysis for the parallax error is a good guideline for design of the combat vehicle with gun having good system hit probability.

Keywords: system hit probability, combat vehicle, target, gun, fixed bias.

Pages: 27 - 29 | DOI: 10.15224/978-1-63248-140-5-40

3. ON THE AUTOMATIC DIMENSIONING OF TECHNICAL DRAWINGS

Authors: A. G. SIOZOS , K. G. KAKOULIS

Abstract: Traditional (2-D) technical drawings are still used by people involved in the production chain to manufacture parts to exact specifications. Of the many processes involved in the production of a good technical drawing, dimensioning is one of the most tedious, time-consuming and error prone. Most state of the art CAD systems generate 2-D technical drawings from 3-D models automatically. They also place dimensions automatically, however, in a rather primitive way. In practice, the automatically generated dimensions are the starting point for a manual improvement of the dimension positions. In this paper, we present fast and efficient techniques for the automatic placement of dimensions to 2-D technical drawing, which we have implemented and incorporated into a commercial CAD system. The dimensions produced follow the basic drawing standards and do not produce redundant dimensions.

Keywords: CAD, Automatic Dimensioning, Automatic label placement, technical drawings

Pages: 30 - 34 | DOI: 10.15224/978-1-63248-140-5-41

4. THE EFFECT OF TURBULENCE MODEL VARIATION ON FLAME PROPAGATION OF CNG AS A FUEL IN 4.-VALVE ENGINES

Authors: ZORAN JOVANOVIC , ZORAN MASONICIC

Abstract: In this paper some initial results concerning the evolution of flame propagation of CNG as a fuel in 4-valve engines with tilted valves were presented. Results were obtained by dint of multidimensional modeling of reactive flows in arbitrary geometry with moving boundaries. During induction fluid flow pattern was characterized with organized tumble motion followed by small but clearly legible deterioration in the vicinity of BDC. During compression the fluid flow pattern is entirely three-dimensional and fully controlled by vortex motion located in the central part of the chamber. The effect of turbulence model variation on flame propagation was tackled as well. Namely, some results obtained with eddy-viscosity model i.e. standard k-ε model were compared with results obtained with k-ξ-f model of turbulence in domain of 4-valve engine in-cylinder flow. Some interesting results emerged rendering impetus for further quest in the near future. In the case of combustion all differences ens

Keywords: automotive flows, turbulence modelling

Pages: 35 - 39 | DOI: 10.15224/978-1-63248-140-5-42

5. OPTIMUM POSITION OF ACOUSTIC EMISSION SENSORS FOR SHIP HULL STRUCTURAL HEALTH MONITORING BASED ON DEEP MACHINE LEARNING

Authors: GEORGE GEORGOULAS , PETROS KARVELIS , VASILIS TZITZILONIS , VASSILIOS KAPPATOS

Abstract: In this paper a method for the estimation of the optimum sensor positions for acoustic emission localization on ship hull structures is presented. The optimum sensor positions are treated as a classification (localization) problem based on a deep learning paradigm. In order to avoid complex and timeconsuming implementations, the proposed approach uses a simple feature extraction module, which significantly reduces the extremely high dimensionality of the raw signals/data. The optimum sensor position is defined by the maximum localization rate. In simulation experiments, where a stiffened plate model was partially sunk into the water, the localization rate of acoustic emission events in a noise-free environment is greater than 99.5 %, using only a single sensor.

Keywords: Acoustic emission, optimum sensor positions, ship hull, deep machine learning

Pages: 40 - 43 | DOI: 10.15224/978-1-63248-140-5-43

6. EFFICIENT SPIRAL ALGORITHM FOR CUTTING BIT MAPPING ON THE MICRO TRENCHER BLADE

Authors: YU JAE-HO , ALMAS ANJUM , ANEES AHMAD

Abstract: This paper presents a novel algorithm for placement of circular cutting bits on a 141.36 inch circular trencher blade for hard rock cutting to be able to lay fiber optic cable of varying width. The blade is divided into 6 x segments of 60 degree each. The spiral algorithm calculates the exact angle of hit, no. of bits and the angle of exposure to precisely cut the required width of hard rock patch for fiber optic cable lying. With the no. of bits and angle known the best cutting blade speed and speed of wheeled machine can be calculated to obtain précised outcome. Given the type of material to cut the algorithm can also estimate based on the above mentioned parameters the running cost of trenching blades/ km in terms of bits replacement to forecast the exact cost of trenching. The algorithm simulation on hard rock shows as the no. of bits are reduced on the circular trencher blade the bits replacement rate / km increases, the effect is even worse if simultaneously the bit ground penet

Keywords: Component, Trenching, cutting bits, circulat blade, rpm, speed, Micro trencher, Mean Time to Failure ( MTF).

Pages: 6 - 10 | DOI: 10.15224/978-1-63248-140-5-35

7. A BIOMIMETIC MEMS DIRECTION FINDING ACOUSTIC SENSOR BASED ON METALMUMPS PROCESS

Authors: MUHAMMAD ALTAF HUSSAIN , MUHAMMAD SHOAIB , SYED OSAMA BIN ISLAM

Abstract: This paper presents the design and finite element method (FEM) modeling of MEMS acoustic sensor optimized using the design rules of the commercially available Metal-Multi User MEMS Process (MetalMUMPs). The acoustic sensor is modeled with a structural layer of Nickel with 20 μm thickness. The acoustic sensor is designed for the detection of sound direction where the displacement amplitude of the sensor plates vary with the applied pressure and angle at specific sound frequency. Moreover, the stress induced in the sensor, corresponding to the input sound waves, is analyzed using FEM simulations and geometric modifications are made to have the stress in the sensor microstructure less than the yield stress of the Nickel. This allows to minimize the effect of mechanical fatigue on the proposed MEMS acoustic sensor performance.

Keywords: Acoustic Sensor, MEMS, PTM, MetalMUMPs, FEM, Yield Strength

Pages: 11 - 15 | DOI: 10.15224/978-1-63248-140-5-36

8. NUMERICAL ESTIMATING THE SHOCK STRENGTH OF AUTOMOBILE CLUTCH DISC HUB

Authors: ALI DURMUS , CIHAT GUL , MEHMET ONUR GENC

Abstract: Clutch disc hub is provide torque transmission between clutch disc drive plate and gearbox input shaft. Therefore disc hub is expected to show high endurance and storage under high torsional forces The aim of this paper is to investigate shock strength of a clutch disc hub numerically with finite element analysis. There are many engine and transmission elements in vehicle such as connecting rods, engine gears, bearing caps and clutch hubs need to have high resistance under high forces during driving conditions. In this study a clutch hub models shock strength simulation was obtained by finite element analysis with powder material and steel (will be produced by machining). Depending on the clutch hub geometry and materials such as powder materials and steel, the absorbed energies were calculated with finite element method and comparison between two materials were investigated.

Keywords: shock strength, clutch hub, charpy test, powder material

Pages: 16 - 19 | DOI: 10.15224/978-1-63248-140-5-37

9. ARTIFICIAL MICROSTRUCTURE GENERATION OF DP590 STEEL USING MULTI-OBJECTIVE TLBO METHODOLOGY

Authors: ASHWANI VERMA , RAVINDRA K. SAXENA

Abstract: Micromechanical modelling of dual phase (DP) steel is used to predict the macroscopic tensile properties. The DP steel is widely used due to its good formability characteristics. The DP steels are having high strength and high ductility for suitable application in automobile industries. For the micromechanical analysis of the DP steel, the representative volumetric element (RVE) is generated from the microstructure of the steel obtained using scanning electron microscope at a suitable magnification showing explicit ferrite and martensite grains. In the present work, a model is formulated using Teacher- Learner based optimization (TLBO) algorithm to generate the artificial microstructure of the DP590 steel. The micromechanical modeling is performed to get the tensile macroscopic response. The model is able to predict the artificial microstructure and the tensile stress-strain of the DP590 steel with a reasonable accuracy.

Keywords: DP590 steel, micromechanical modeling, artifical microstructure, TLBO, finite element method, MATLAB.

Pages: 20 - 23 | DOI: 10.15224/978-1-63248-140-5-38

10. MUZZLE VELOCITY ERROR ESTIMATION AND SYSTEM ACCURACY PREDICTION

Authors: GUN IN KIM , HWAN IL KANG , HYUN SOO KIM

Abstract: To predict the system accuracy, we should calculate the measure of the muzzle velocity error and elevation difference according to 1 m/s change of muzzle velocity. The magnitude of the muzzle velocity may be obtained by weighed sum of three quantities: the percentage errors of projectile weight, propellant weight and the volume of the chamber. The elevation difference according to 1 m/s change of muzzle velocity can be obtained from the multivariable function. The inputs of the multivariable function are: the distance that the bullet falls due to gravity, the distance from the launch position to the target, muzzle velocity, tangent angle from the launch position to the target. The error on the target due to muzzle velocity error can be a product of two quantities: the measure of the muzzle velocity error and elevation difference according to 1 m/s change of muzzle velocity. To predict the system accuracy, we use the accuracy function having the standard deviation and then we may obtain

Keywords: system accuracy, muzzle velocity, target, accuracy function, projectile, propellant.

Pages: 24 - 26 | DOI: 10.15224/978-1-63248-140-5-39